1. Field of the Invention
The present invention relates to a continuous tag printing machine and, more particularly, to a system for automatically differentiating the longitudinal sizes of tags which are charged in the form of a continuous web into the continuous tag printing machine.
2. Description of the Prior Art
A printing machine using a continuous tag web as its printing medium is charged with continuous tags of various sizes, which are selected in accordance with either the amount of indicia to be printed or a printing format. Moreover, it is necessary to determine at the printing machine whether the sizes of the continuous tags charged correspond to the size and placement of their printed contents. It, therefore, becomes essential to differentiate among various tag sizes.
For the aforementioned tag sizes, the widthwise or transverse sizes can be automatically differentiated on the basis of tag sensing signals coming from respective sensors by fixing one side of the continuous tag web, and by arranging a desired number of sensors in the vicinity of the other side of the continuous tag web arrayed in the transverse direction. However, the longitudinal sizes of the tags are difficult to automatically differentiate. Therefore, it is customary for the operator to feed the longitudinal sizes to the printing machine as inputs by the use of a switch, an input key or the like.
This is disadvantageous in that it is necessary to input the longitudinal tag sizes for each replacement continuous tag web. Another disadvantage is that an erroneous feeding operation will frequently cause improper printing of tags or the inability to print tags altogether.